This invention relates to the treatment of the ceramic and other earthenware bodies, and is particularly but not exclusively concerned with the treatment of fired clay bodies in the form of ceramic garden or patio pots. Other applications include hanging pots, wall hangers, house bricks and ceramic roof tiles, or any other ceramic, fired clay or earthenware article.
One particular problem associated with ceramic pots and containers intended for use outdoors eg in gardens, patios and on walls, is the tendency towards damage due to the action of frost. It is a well-known fact that when water is absorbed into the walls of porous earthenware pots, freezing temperatures will case that water to expand and the pots will often crack, laminate, effloresce or simply fracture.
Attempts have been made in the past to obviate this problem by making surfaces of the pot water repellent or waterproof, eg by glazing. If the glaze is applied while there is still some moisture in the earthenware then freezing temperatures will nevertheless have the same detrimental effect on the ware. Further, it has been found that because of the environment in which garden or patio pots are used and located, damage is often suffered by; the glaze, allowing ingress of water or moisture which is acted upon by the freezing temperature so that expensive and attractive pots are damaged and often destroyed.
Some earthenware pots are decorated by decalcomania transfers or by hand painting, the decoration being then fired onto the surface. It is preferred that the surface area of the pot where the transfer or paint is to be applied is smooth and for this reason the surface is sometimes glazed before applying the transfer or other art work. This process involves an additional firing which adds to the cost of the decorated ware.
It is an object of the invention to provide a method of treating ceramic or other earthen ware that does not suffer from some or all of the above disadvantages and which results in a pot which reduces the damage by reason of freezing temperatures acting on the ware, and/or to provide improvements generally.
A further alternative object is to attempt to provide a method of treating earthen ware and the like to enable it to be more receptive to decals or other decoration without the need for glazing the ware before decorating it.
A further alternative object includes attempting to provide ceramic or other earthen ware which does not suffer from the known limitations and faults of ware produced by conventional processes.